This invention relates to an automatic seat belt device and, more particularly, to improvements of an automatic seat belt device essentially installed in each seat of a motor vehicle and applied automatically to an occupant of the seat upon closing of a door, so-called a "passive seat belt device".
The conventional automatic seat belt device, as shown by dotted broken lines in FIG. 1, engages an outer belt B and an inner belt C through a ring joint D. When a door 1 is opened, the ring joint D slides down along the outer belt B. Thus, the engaging position of the outer belt B with the inner belt C through the ring joint D is moved toward a seat cushion E, so that an interval h between the engaging position and the upper surface of the seat cushion may become narrow. This causes an occupant's riding space to become very narrow, and may cause inconvenience to the occupant riding in a vehicle. In order to eliminate this disadvantage, proposals have been made to provide a guide member, for guiding the base F of the inner belt C upwardly and forwardly and attached to a retractor side, or an anchor mounted under the door with long boots for retaining the lower end portion of the outer belt B at a higher position. The former has, however, a complicated mechanism which introduces an expensive cost and lacks reliability as a seat belt, while the latter creates a large space between the occupant and the lower portion of the outer belt to thus deteriorate its performance in confining the occupant.